God
Formal Statement
By God, I mean a being absolutely infinite — that is, a substance consisting of infinite attributes, each of which expresses eternal and infinite essentiality. "Absolutely infinite" means no attribute that expresses reality can be denied of it.
In Plain Language
This is not a definition of a personal creator. Spinoza's God is substance taken to the absolute maximum: it has every possible attribute, each one infinite in its own kind. The key word is "absolutely" — not just infinite in one respect (like an endless line), but infinite in every respect, lacking no form of reality whatsoever. This definition is a logical bomb: once you accept it alongside the earlier definitions, monism becomes almost inevitable.
Why This Follows
We already have substance (gs-01) and attribute (gs-02). God is now defined as the substance that holds all possible attributes — the maximally real substance. This sets the stage for showing that such a being must exist and must be the only substance.
God is absolutely infinite substance, consisting of infinite attributes each expressing eternal and infinite essence.
Connected Concepts
Why does Spinoza insist on "absolutely" infinite rather than just "infinite"? What would be lost without that distinction?